The field of the disclosure relates generally to rotary machines and, more specifically, to bearing cages for roller bearing assemblies.
At least some known turbomachines include one or more shafts which are rotatably supported by several known bearings, typically of a rolling-element type. These known bearings in the turbomachine are usually a combination of roller bearings and ball bearings, and are enclosed in sumps, which are pressurized and receive an oil flow for lubrication and cooling. The roller bearings support radial loads induced by the shaft and the ball bearings support radial and thrust loads induced by the shaft.
Some known roller bearing assemblies include an annular inner ring coupled to the shaft and an annular outer ring, with a plurality of rollers circumferentially spaced about a center axis therebetween. The roller bearing assembly further includes a bearing cage that is positioned between the inner and outer rings to receive the rollers. These roller bearing assemblies may also be used in a planetary bearing assembly. At least some planetary bearing assemblies include 3-6 roller bearing assemblies circumferentially spaced about a planetary center axis. Each roller bearing assembly is rotatable about its center axis, and the entire planetary bearing assembly is rotatable about its planetary center axis. With multiple axes of rotation, some known planetary bearing assemblies load and unload the rollers such that when the rollers are unloaded, centrifugal forces induce contact with the bearing cage. As such, the rollers increase contact with the bearing cage, thereby accelerating wear within the roller bearing assembly.